body {
  margin: 0;
  padding: 0;
  font-size: 16px;
}
*{
  box-sizing: border-box;
}
#h3{
  text-shadow: 5px 5px 5px #FF0000;
  animation:myfirst 5s;
}
@keyframes myfirst
{
	from {background:red;}
	to {background:yellow;}
}
